docs: def get_subgraph_by_induction(graph, nodes: Iterable[BaseEntity]):
      """Induce a sub-graph over the given nodes or return None if none of the nodes are in the given graph.
  
      :param pybel.BELGraph graph: A BEL graph
      :param nodes: A list of BEL nodes in the graph
      :rtype: Optional[pybel.BELGraph]
      """
      nodes = tuple(nodes)
  
      if all(node not in graph for node in nodes):
          return
  
      return subgraph(graph, nodes)